1. Field of the Invention
The present invention relates to a method for joining articles by a laser beam, electron beam or other energy beam as well as an apparatus for controlling the method.
2. Description of the Prior Art
Joining of a plurality of articles is a fundamental, indispensable technique in numerous industrial field. There are a number of joining methods, of which welding is one of the most frequently practiced.
Typical welding methods are arc welding and gas welding. Recently, however, a welding method using an energy beam, i.e., a beam having high energy density, such as a laser beam or an electron beam, has been developed. This welding method is hereinafter referred to as the beam-welding method.
The high energy-density of energy beam offers a number of advantages. However, the total energy efficiency in the beam-welding method is lower than that of the arc welding and gas welding methods because of the low efficiency of conversion of electric energy to beam energy. The conventional beam welding methods are explained with reference to FIGS. 1A and 1B.